The stars are aligning for a winnable and worthwhile fight on U.S. policy in Afghanistan in the next several weeks: stopping the Obama Administration from sending more troops.

It should be winnable, because: the public is against sending more troops, the overwhelming majority of Democrats are against sending more troops, key Democrats in Congress have begun to speak out against sending more troops, the Obama Administration is divided, President Obama hasn't taken a public position, and the Obama Administration has signaled that it will not take a public position for several weeks. The delay gives opponents time to mobilize, more Members of Congress the opportunity to speak out before the Administration solidifies its position.

It's a worthwhile fight, among other reasons, because if we want the U.S. government to seriously pursue diplomatic efforts to resolve the Afghanistan conflict politically, we have to jam them up on the "military option."

On October 1, the U.S. plans to talk to Iran. This is happening, in part, because Washington doesn't see a "military option" in Iran now. Part of the reason Washington doesn't see a military option in Iran is because they don't perceive the U.S. public as supporting a military option.

Denying the Pentagon access to more U.S. troops isn't the most subtle, nuanced way to influence U.S. policy. But it's the main lever that the public has.

The political battle over more U.S. troops isn't a battle over what's going to happen in Afghanistan next month. The troop increase that President Obama approved earlier this year has not yet been completed. It's a political battle about what's going to happen in the next several years.

Indeed, if President Obama were to approve 10,000 more troops beyond the increase already approved, the likely effect over time would be simply to replace the troops from other countries that are almost certain to leave.

Canada's Prime Minister has recently reaffirmed that Canada's 2,500 troops are leaving in 2011.

Italy's Prime Minister Berlusconi says Italy's 2,800 troops should leave Afghanistan "soon." A key coalition partner says they should leave in three months.

British Prime Minister Brown has told the US he wants to cut UK troop numbers from more than 9,000 to fewer than 5,000 in "three to five years, maximum," the Independent recently reported.

That's about 10,000 troops right there. Of course, these withdrawals are likely to spur others.

In 2011, the "foreign" military forces in Afghanistan will be overwhelmingly U.S. forces, even more so than today. That's the world that would be put in place by the U.S. troop increase that's being proposed.

Now is the time for Congress and the American people to speak up. If the Administration publicly commits itself to sending more troops, it will be much harder for Democrats in Congress to oppose.